Cubic GaN On Large-area Silicon (100) Dies
Gallium Nitride (GaN) and its alloys (i.e., III-nitride semiconductors) are the backbones of solid-state lighting, and the next-generation RF and power electronics. Today, most research and development in this material system are focused on its conventional, hexagonal (i.e., wurtzite) phase although its cubic (i.e., zincblende) phase has more inherent advantages such as: No polarization in the <100> growth direction, smaller bandgap, smaller electron-heavy hole effective masses, smaller Auger loss, larger optical gain, shorter radiative recombination lifetime, lower p-doping activation energy, higher hole mobility, and larger conduction band offset. Cubic III-nitride semiconductors might thus enable next-generation devices such as efficiency-droop-free III-nitride visible light-emitting diodes (LEDs) and as-grown, normally-off AlGaN/GaN power transistors. However, the synthesis of cubic GaN has not been an easy task due to its metastability.